Homogeneous core wire protective cleaning tip

ABSTRACT

A brush for use on sensitive surfaces includes a twisted wire core having a handle end and a bristle end, and a plurality of bristles extending radially outward from a portion of the wire core defining a bristle block. The brush further includes a protective tip integrally formed on the wire core at the bristle end for preventing the brush from damaging sensitive surfaces. The wire core and the protective tip are formed from the same material.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 61/149,034, filed on Feb. 2, 2009, which is herein incorporated byreference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to mechanical abrasion cleaningtechnology, and, more particularly, to a cleaning apparatus having aprotective tip that is less prone to scratch, scar or damage sensitivecleaning surfaces, and further to a device and a method of making thesame.

BACKGROUND OF THE INVENTION

Brushes for cleaning the inner surfaces of vessels are well known in theart. One type of such brush is the twisted in wire brush, which iscommonly used in a variety of applications including, but not limitedto, hole cleaning, sanding, deburring or lubricating, tube or vesselcleaning, beaker cleaning, pistol, rifle and shotgun cleaning, medicalequipment cleaning, medical and dental procedures, medical applicationsand the application of personal care products including mascara and thelike. Twisted in wire brushes are also known as spiral, tube flue,bottle, pipe, boiler or power brushes, and are generally comprised of aplurality of bristles held and secured by a pair of twisted metal wireswhich form the core of the brush. The bristles are often formed fromsome type of acrylic fiber and extend radially from the core orlongitudinal axis of the brush, generally resulting in a roughlycylindrical appearance. It will be readily appreciated, however, thatthe bristles may be formed from any suitable material including metal,such as stainless steel, brass or bronze, nylon, Teflon, polypropylene,horse or hog hair, depending on the specific use. Moreover, depending onthe specification application, the ends of the brush can also vary. Forexample, a brush may have a rough-cut tip, a rounded tip or a bristledor fan tip, and can have a long end or handle, a short end, or afinished end having various configurations such as a ring or loop.

During the manufacturing of known brushes, the core of the brush, i.e.,the twisted wire, is often cut at a distal or bristle end thereof,opposite the handle end. This cutting may leave a sharp, uneven andunfinished end. Known twisted in wire brushes may also employ acontinuous end where the wire is doubled back on itself prior totwisting, as shown in prior art FIGS. 1A and 1B. The subsequent twistingto secure the bristles often leaves this continuous end (opposite theunfinished end) with rough, sharp and uneven surfaces and edges as well.This is highly undesirable in applications as discussed in detail below,where a smooth and frictionless surface is needed at the end of thebrush so as to be less prone to scratch, scar or damage sensitivecleaning surfaces.

As alluded to above, twisted in wire brushes are used in manyapplications where an unfinished or uneven end of a brush would causescratching or other damage. For example, such twisted wire brushes haveparticular application in the medical field where they are used for,among other things, cleaning the inner surfaces of catheters,arthroscopic devices, cameras, etc. Moreover, specialized brushes havebeen known to be used directly on or in soft and delicate tissues orcavities such as blood vessels. Accordingly, there is a need to have afinished tip on twisted in wire brushed so that a smooth andfrictionless surface is presented to the interior of the vessel orcavity to be cleaned.

In view of this need, there exist several different known technologiesand methods which are used to form rounded or smooth ends on twistedwire brushes in an attempt to prevent the ends of the wire core fromscratching or otherwise damaging the inner walls of a vessel. One suchmethod involves press-fitting or hand-crimping a small metal cap on theend of the brush to form a smooth and rounded tip. This process,however, is quite labor-intensive and time consuming, resulting in highlabor and production costs. In addition, this method often results ininconsistent tip orientation, i.e., the metal caps are often improperlyseated on the end of the brush. This increases the chance that the capswill be dislodged or displaced, which can itself create an unevensurface or expose the unfinished end of the brush, thereby resulting inscratching or damage to the interior surface of the cavity beingcleaned. Moreover, this method of forming a smooth tip may result ininconsistent core wire adhesion and only allows for limited dimensionaloptions.

Another known method of providing a smooth end on a twisted wire brushinvolves dipping the end of the brush into a vat of plastic or acrylicand then exposing the tip to visible or ultraviolet light to cure theplastic or acrylic. Such process results in the formation of aprotective plastic or acrylic tip on the end of the brush. This method,however, often results in a rough surface texture and inconsistent tipdimensions due to both the viscosity of the plastic or acrylic used, andthe time it takes for such plastic or acrylic to cure. Such rough tipsare highly undesirable for use in applications where a smooth surface isneeded to prevent damage to soft and sensitive vessel walls that may beprone to scratching or other damage. Moreover, even when employing thismethod, it is possible that the wire core section may protrude throughthe plastic tip during use, thereby exposing a sharp and unfinished endof the core wire section to such sensitive surfaces. These plastic oracrylic tips are also prone to dislodgment, which can result in exposureof the unfinished core wire section. Additionally, manufacturing timemay be greatly increased due to extended curing times, and hazardousfumes may result from the dipping and curing process. Light curing thetips also involves semi-automatic or manual processes that may be timeconsuming and may result in increased labor and production costs.Moreover, as will be readily appreciated, in many applications, it isdesirable to color code the tips of the brushes so as to identify thebrush by type, size or use. The acrylic/plastic tip method, however,only allows for limited/inconsistent tip color options.

Insert molding is yet another known method for forming a rounded tip onthe end of a brush, and involves placing the end of the brush into amold and then injecting plastic into the mold. When the plastic hardens,the brush end is removed from the mold, producing a hardened, roundedplastic cap on the end of the brush. This method, likewise, is notwithout its drawbacks. Due to the high cost of mold making, it isimpractical for small production runs. In addition, this process mayresult in core wire protrusion through the plastic tip, either from themolding process or through forces associated with cleaning. In addition,the protective tip may be inadvertently dislodged from the wire coreduring use, resulting in exposure of the sharp end of the core wire andpotential damage to interior vessel walls. This method also does notallow for many variations in tip sizes and may result in inconsistenttip orientation. Such an inconsistent or angled tip orientation mayitself cause damage to the surface to be cleaned or may cause the tip tobe jarred loose during cleaning, resulting in exposure of the core wire.

Fan-tip twisted in wire brushes are another attempt to provide aprotective surface on the brush end. This type of brush features“fanned” bristles on the brush end in attempt to shield the surface tobe cleaned from the end of the brush. Fan-tip twisted in wire brushes,however, are less commercially attractive, have limited fan tipdimensions, and have increased production costs. In addition, duringuse, depending on the interaction between the bristles and the surfacebeing cleaned, the core wire may still be exposed through the fan tip,thereby potentially causing damage to any sensitive surface.

Another inherent problem with twisted in wire brushes in general istheir tendency to unravel when used in applications such as medicalapplications and gun cleaning where a reasonable force is necessary toeffectuate cleaning, deburring, etc. In such applications, the forcesgenerated by the cleaning motion will sometimes cause the twisted wirecore to come unraveled and the bristles to become dislodged. This maycause exposure of the core wires, making the vessel more prone toscratching and other damage, and also may result in the leaving ofundesirable debris, e.g., bristles or caps, within the vessel. There istherefore a need to increase the structural strength of such brushes soas to prevent unraveling in applications where a reasonable force isneeded to effectuate cleaning, deburring, lubricating, etc.

In view of the problems associated with known techniques and methods forforming a rounded or smooth tip on the ends of twisted wire brushes,there is a need for an improved brush and method for forming a smoothand rounded tip on the end thereof so as to prevent unintended scarring,scratching or damage to sensitive surfaces.

SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of the present invention toprovide a brush having a protective tip.

It is another object of the present invention to provide a brush capableof cleaning the interior surface of a vessel without scratching orotherwise damaging such surface.

It is another object of the present invention to provide a brush that isproduced in an environmentally friendly manner, without the use ofacrylics or plastics.

It is another object of the present invention to provide a brush forcleaning the interior surface of a vessel having a protective tip thatwill not trap contaminants on its surface.

It is another object of the present invention to provide a brush havinga protective tip that is less prone to dislodge from brush during use.

It is another object of the present invention to provide a brush havinga protective tip that has less surface friction than known tip surfaces.

It is another object of the present invention to provide a twisted inwire brush having an increased structural strength so as to preventunraveling of the brush or bristles in certain applications where areasonable force is needed.

It is yet another object of the present invention to provide a method offorming a protective tip on a brush that will be cost-effective in bothlarge and small production runs.

It is yet another object of the present invention to provide a method offorming a protective tip on a brush without the need to modify theexisting technology used to manufacture such brushes, thereby addinglittle or no additional cost to the fabrication process.

It is yet another object of the present invention to provide a method offorming a protective tip on a brush that adds minimal time and cost tothe production process.

It is yet another object of the present invention to provide anapparatus for forming a protective tip on the end of a wire brush.

It is yet another object of the present invention to provide anapparatus for forming a protective tip on the end of a wire brushwithout subjecting the bristles of the brush to excess heat.

It is therefore a general object of the present invention to provide abrush having a protective tip. This protective tip is smooth and roundedso as to prevent scratching or damage to sensitive and delicate interiorsurfaces of vessels to be cleaned. The protective tip also increases thestructural strength of the core wire so as to prevent unraveling of thecore and bristles in certain applications where a reasonable force isneeded to effect cleaning, lubricating, etc.

It is also a general object of the present invention to provide a methodof forming a protective tip on a brush, which generally comprises thestep of manufacturing a brush by a known process and further comprisingthe step of holding the brush adjacent to, or in contact with, anelectrode, laser or other heat generating assembly and “melting” apre-constructed core wire section of the brush into an integral, smoothand inseparable protective tip. This section, once fused is unable to beseparated from the brush core, thus reducing the risk of cleaningsurface damage.

It is further a general object of the present invention to provide anapparatus for forming a protective tip on the end of a wire brush thatincludes a means for holding the brush relevant to an electrode or laserand a heat shield to prevent the presentation of any excess heat to thebrush bristles.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood from reading thefollowing description of non-limiting embodiments, with reference to theattached drawings, wherein below:

FIG. 1A is a side plan view of a prior art twisted in wire brushrepresentative of a known cleaning apparatus prior to fabrication, andshowing the placement of the bristles;

FIG. 1B is a side plan view of a prior art twisted in wire brushrepresentative of a known cleaning apparatus prior to fabrication, andshowing an alternative placement of the bristles;

FIG. 2A is a side plan view of the wire core of a prior art twisted inwire brush according to a known configuration and prior totwisting/fabrication;

FIG. 2B is a side plan view of the prior art twisted in wire brush ofFIG. 2A after insertion of a bristle block and twisting/fabrication ofthe core has been completed;

FIG. 3 is a side plan view of a prior art twisted in wire brush havingan alternative configuration;

FIG. 4A is a side plan view of a continuous end type cleaning apparatushaving an unfinished end in accordance with one embodiment of thepresent invention;

FIG. 4B is a side plan view of a broken nose type cleaning apparatushaving an unfinished end in accordance with one embodiment of thepresent invention;

FIG. 5 is a side plan view of the cleaning apparatus of FIG. 4B andhaving a finished end in accordance with one embodiment of the presentinvention; and

FIG. 6 is a side plan view of an apparatus for forming a protective tipon the end of a twisted wire brush in accordance with one embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is directed to a cleaning device, morespecifically a brush, having a protective tip that is less prone toscratch, scar or damage sensitive cleaning surfaces, and further to amethod and apparatus for making the same. The brush is especiallyadapted to be used for cleaning the interior surfaces of vessels whereinan unfinished end of a brush may cause damage to such interior surfaces,such as in medical applications, for example, the cleaning of catheters,arthroscopic devices, cameras, etc., and for use in cleaning pistols,rifles and shotguns.

As discussed above, FIGS. 1A-3 show various configurations of prior arttwisted in wire brushes at different points of the fabrication process.FIGS. 4A and 4B show two different configurations of twisted in wirebrushes prior to forming the inventive protective tip, as discussed indetail below.

The brush may be fabricated in the customary manner by using a pliablemetallic wire, reversibly folded back upon itself. A plurality ofbristles of predetermined length are placed between the two coextensiveleg portions of the wire, as shown in FIGS. 1A and 1B. The wire is thentwisted to form the core of helical configuration, which grips thebristles at the midpoint of their length, causing the filaments to becrimped and folded in half. The outer tips of the bristles define aroughly cylindrical shape of predetermined diameter, or a conical shape.The bristles may be further trimmed to arrive at various additionalshapes, such as the configuration shown in FIG. 2B. While this is anexemplary method of forming a cleaning apparatus, and more particularlya twisted in wire brush, it will be readily appreciated that anyfabrication process or method for forming twisted in wire brushes knownin the art may be employed, without departing from the scope of thepresent invention.

For example, it will be readily appreciated that a plurality of wiresmay be used in place of the single wire described above. In such asituation, the plurality of wires may be placed adjacent one another, aplurality of bristles placed between the wires, and the wires twistedtogether to form a core of helical configuration and to anchor thebristles in place. A brush produced by this method is shown in FIG. 3.Other methods and configurations of forming wire brushes and twisted inwire brushes are known in the art and may be incorporated in the currentdesign without departing from the scope of the present invention.

Whether the brush is constructed from a single wire folded back onitself, or a plurality of wires, the distal or bristle end of the brushadjacent the bristle block or head portion is exposed and uncovered,which, if used in cleaning sensitive or soft surfaces, may damage orscratch such surfaces. As alluded to above, the brush may also be eitherof the “continuous end” type, such as that shown in FIG. 4A, where thebristle block is closest to the folded-over point of the wire core, orthe “broken nose” type, such as that shown in FIG. 4B, where the bristleblock is closest to the unfinished wire ends. In the case of acontinuous end brush, sharp edges 124 may still be present as a resultof the tight twisting of the wire. In addition, such continuous endbrushes may have a void 126 or depression at the bristle end 120 thereofthat is susceptible to trapping contaminants that can then beundesirably introduced in the vessel to be cleaned. The presentinvention is therefore equally applicable to continuous end brushes,such as shown in FIG. 4A, and broken nose brushes, such as shown in FIG.4B.

As noted above, FIGS. 4A and 4B show a cleaning apparatus 100 of thepresent invention prior to the forming of the protective tip. As can beseen from FIG. 4B, the two coextensive leg portions 114,116 of thetwisted wire core 110 of a broken nose brush may have very sharp anduneven end surfaces 128 at the bristle end 120 thereof. Moreover, evenwith continuous end brushes, the bristle end may still have sharp anduneven edges 124 and/or a contaminant trapping void 126 at the bristleend 120 thereof as a result of the tight twisting of the coextensive legportions, as shown in FIG. 4A.

As shown in FIG. 5, the present invention, therefore, contemplates acleaning apparatus 100, more specifically a twisted in wire metal brush,having a helical metallic wire core 110, a bristle block or head portion112 formed from a plurality of discrete bristles 132, a handle fitted orformed on the terminal end or handle end 122 of the twisted wire core110, and a protective tip 130 on the distal or bristle end 120 of thetwisted wire core 110. The helical metallic wire core 110 is made up ofat least two coextensive leg portions 114,116 which are twisted aroundeach other and which anchor the bristle block. The metallic wire coremay be comprised of nickel alloys, titanium alloys, stainless steelalloys, carbon steel alloys, cobalt alloys or aluminum alloys, althoughother metals or metal alloys may be used without departing from thescope of the present invention.

As best seen in FIG. 5, the cleaning apparatus of the protective tip 130formed on the bristle end 120 of the brush prevents the brush fromscratching, scarring or damaging sensitive cleaning surfaces, asdiscussed herein. This protective tip 130 is formed on the bristle end120 of the brush, after the twisting of the core 110 to anchor thebristle block 112, in a post-production process.

To form a smooth and substantially rounded surface on the bristle end120 of the cleaning apparatus 100, the present invention useshigh-energy fusion welding to “melt” the bristle end 120 of the brush.In the case of a “broken nose” brush, welding is used to melt the endsurfaces 128 of the coextensive leg portions 114, 116 of thepre-constructed core wire section 110 of the cleaning apparatus 100 intoa consistent, smooth and inseparable protective tip 130. In the case ofa “continuous end” brush, welding the bristle end 120 also melts andeliminates any sharp or uneven edges 124 of the cleaning apparatus 100,and likewise forms a consistent, smooth and inseparable tip 130. Inaddition, melting of the bristle end 120 also eliminates any contaminanttrapping voids 126 that may be present. Once fused, the coextensive legportion 114, 116 are unable to be separated from one another, and thetip 130 is also inseparable from the cleaning apparatus 100, thusreducing the risk of cleaning surface damage. As will be readilyappreciated, welding of the bristled end 120 of the brush results in ametallurgical bond between the tip 130 and the core wire section 110 ofthe brush. Importantly, no chemical curing agents used to form the tip,which makes the present invention especially well suited for use inmedical applications.

Specific welding technologies such as Laser, Gas Tungsten Arc Welding(GTAW), Plasma Arc Welding and Electron Beam Welding may be used to meltthe bristle end 120 to form the protective tip 130. In particular, thepreferred parameter range is 0.001 Milliamps to 200 Amps for GasTungsten Arc Welding, 15 Kv-200 Kv for Electron Beam Welding and 1Amp-200 Amps for Plasma Arc Welding, although other parameters may beused. For Laser technology, near ultra violet and/or near infra redlaser sources are preferred, although other wavelengths may be used toachieve the objects of the present invention.

The welding or “melting” of the bristle end of the core wire section 110allows for the formation of different surface geometries depending uponthe welding parameters, including spherical and variations thereof. Themelted or welded protective tip 130 also guarantees a smooth, cleansurface that will not trap contaminants on its surface. In addition, thesurface friction of the melted or welded tip can be significantly lessthan that of plastic-dipped tips, which is important in certain medicalapplications. Moreover, a further benefit of the integrally formedhomogeneous tip 130 is that it allows for passivation of the brushmaterials, especially in the case a brush having a stainless steel orstainless steel alloy core.

It is a further advantage of the present invention that the protectivetip, once formed, is incapable of being separated from the wire core, asthe core and protective tip is a single welded piece, i.e., the corewire section 110 and the protective tip 130 are homogeneous. Asdiscussed herein, prior art cleaning brushes often employ separateelement tips, either of plastic or metal, that can come loose from thebrush when it is retracted or moved within the cavity, which, in turn,exposes the core wire making the surface susceptible to damage from theunprotected end of the brush. Moreover, it will be readily appreciatedthat one of the advantages of using welding, melting or joiningtechnology in lieu of plastic tips is that plastic tips require the useof a large and expensive mold apparatus to form such tips. Consequently,the use of plastic tips is only economically viable with very largeproduction runs, otherwise the high cost of the injection mold would notbe justified. In stark contrast to known methods, the forming of theprotective tip 130 of the present invention is fast, cost-effective andadds very little time and expense to the existing fabrication process.

A further advantage of the melted protective tip formed on the brush ofthe present invention is that such tip increases the structural strengthof the brush itself, which aids substantially in ensuring that the legportions 114,116 do not become unraveled. This is a problem in certainapplications, such as medical applications and gun cleaning, where areasonable force is needed to effect cleaning, lubricating, deburring,etc. Moreover, the protective tip may be formed by the method andapparatus of the present invention, as discussed below, irrespective ofdiffering diameters, lengths and materials of the core wire section 110.

As alluded to above, it will be readily appreciated that the existingtechnology used to manufacture twisted in wire brushes need not bemodified in order to form the additional protective tip. Therefore,there is minimal additional cost associated with the fabrication of thecleaning apparatus according to the present invention. As noted above,the protective tip 130 is formed after the anchoring of the bristleblock within the core wire section 110, in a post-production process.

Importantly, and in contrast to known brushes and methods for formingprotective tips, the tip of the present invention is formed of the samematerial as the core wire of the brush, from the existing metal of thecore wire at the bristle end 120 of the brush. As such, the presentinvention is advantageous in that there is no need to seek approval forthe composition of the tip material for Food and Drug Administrative(FDA) purposes, as the customary metals and alloys comprising the corewire section 110 have already been approved for use in most cases. Inparticular, the biocompatibility of the protective tip 130 of thepresent invention is the same as the core wire section 110 of the brush.In addition, due to the homogeneity of the protective tip 130 and thecore wire section 110, the wear resistance of the protective tip 130 andthe core wire section 110 are substantially identical.

According to another embodiment of the present invention, an apparatus200 is provided which allows the individual brush to be held adjacent toan electrode, laser or other high energy source and which has a shieldto prevent the presentation of any excess heat to the bristles. FIG. 6shows one possible configuration of the apparatus for forming aprotective tip on the bristle end 120 of a cleaning apparatus 100according to one embodiment of the present invention.

The apparatus 200 comprises a means 212 for holding, supporting, and/orclamping the cleaning apparatus 100 in place. In a preferred embodiment,means 212 grips or supports the cleaning apparatus 100 about the corewire section 110 adjacent the handle end 122. The means 212 may be atable or other surface, a vice, cantilever support, or the like, so longas the apparatus 100 is held statically in place. A cantilever supportbase in combination with an anti-deflection support base may also beused to further restrain the cleaning apparatus 100 for forming theprotective tip 130. The anti-deflection support base prevents thebristle end 120 of the brush from developing deflections during formingof the tip 130.

With particular respect to the support and protective tip formingapparatus, the bristle end 120 is positioned through an aperture orcutout section of a heat shield 214. The heat shield may be supported bya shield support 216 or any other means known in the art. The heatshield may be made of any material so long as it is sufficient toprotect the bristle block 112 from excess heat that may result in thedeformation of the bristles 132 or compromise the integrity of thebristles 132. The apparatus 200 further comprises a welding machine orheat source 218 connected to a power supply 222, and includes awelding/melting tip 220 protruding therefrom that is capable of meltingthe end surfaces 128, sharp edges 124 and/or void 126 of the core wiresection 110 of the cleaning apparatus into a smooth and substantiallyround ball.

It will be readily appreciated that numerous other configurations for anapparatus for forming a protective tip on a cleaning apparatus arepossible without departing from the scope of the present invention. Assuch, any configuration of the means for holding, heat shield and heatsource may be used in combination to achieve the objects of the presentinvention. In addition, any known means for melting or welding metal maybe used as a heat source, such as Laser/Gas Tungsten Arc Welding to(GTAW)/Plasma Arc Welding and Electron Beam welding technology, toachieve the objects of the present invention, as discussed above.

Moreover, in yet another embodiment of the present invention, a methodis provided for forming a protective tip on a cleaning apparatus. Suchmethod involves manufacturing a cleaning apparatus, in particular atwisted in wire brush, by a known process, as hereinbefore described.The method further comprises the steps of positioning the bristle end ofthe cleaning apparatus oh brush adjacent to an electrode or laser,placing a heat shield over the bristle block 112 to shield the bristles132 from heat, and “melting” a pre-constructed core wire section 110 ofthe cleaning apparatus into a consistent, smooth and inseparableprotective tip 130. This section, once fused is unable to be separatedfrom the wire core, thus reducing the risk of cleaning surface damage,as hereinbefore described.

It will be readily appreciated that this process may also be repeated onthe handle end 122 of the brush if such brush is formed in a manner thatleaves sharp, uneven or unfinished edges on the handle end. It may bedesirable to also form a protective tip on the handle end of the brushto prevent the catching of any sharp edges and the like on clothing,etc., or to prevent the lacerating or puncturing of the skin of a user.

Although this invention has been shown and described with respect to thedetailed embodiments thereof, it will be understood by those of skill inthe art that various changes may be made and equivalents may besubstituted for elements thereof without departing from the scope of theinvention. In addition, modifications may be made to adapt a particularsituation or material to the teachings of the invention withoutdeparting from the essential scope thereof. Therefore, it is intendedthat the invention not be limited to the particular embodimentsdisclosed in the above detailed description, but that the invention willinclude all embodiments falling within the scope of this disclosure.

What is claimed is:
 1. A brush for use on sensitive surfaces, said brushcomprising: a twisted wire core having at least two leg portions twistedabout each other in a helical configuration and having a handle end anda bristle end, all of said leg portions being formed entirely from metalor a metal alloy; a plurality of bristles extending radially outwardfrom a portion of said wire core, said plurality of bristles defining abristle block; and a smooth, protective tip integrally formed on saidwire core at said bristle end for preventing said brush from damagingsaid sensitive surfaces, said protective tip being formed by melting orwelding only said bristle end of said wire core such that saidprotective tip is made up of existing material from said wire corewithout the addition of any other quantity of material; wherein all ofsaid leg portions of said wire core and said protective tip arehomogeneous.
 2. The brush of claim 1, wherein said wire core is formedfrom a nickel alloy.
 3. The brush of claim 1, wherein said wire core isformed from a titanium alloy.
 4. The brush of claim 1, wherein said wirecore is formed from a stainless steel alloy.
 5. The brush of claim 1,wherein said brush is a twisted wire brush having a twisted wire coreincluding at least two leg portions twisted about each other in ahelical configuration.
 6. The brush of claim 5, wherein said at leasttwo leg portions are fixedly attached to one another at said protectivetip for preventing unraveling of said leg portions.
 7. The brush ofclaim 1, wherein said bristle block has a cylindrical shape for cleaningor lubricating the interior of a hollow member.
 8. The brush of claim 1,wherein: said protective tip is spherical in shape.
 9. A brush for useon sensitive surfaces, comprising: a plurality of leg portions defininga wire core having a handle end and a bristle end; a plurality ofbristles extending radially outward from a portion of said wire core,said plurality of bristles defining a bristle block; and a smooth,protective tip integrally formed on said wire core at said bristle endfor preventing said brush from damaging said sensitive surfaces, saidprotective tip being formed by melting or welding only said bristle endof said wire core such that said smooth, protective tip includes onlyexisting material from said wire core without the addition of anymaterial to said wire core, and such that a remainder of said wire coreis not melted or welded; wherein said leg portions and said protectivetip are homogeneous.
 10. The brush of claim 9, wherein: said protectivetip is spherical in shape.
 11. A brush for use on sensitive surfaces,said brush comprising: a twisted wire core having two leg portionstwisted about each other in a helical configuration and having a handleend and a bristle end, all of said leg portions being formed entirelyfrom metal; a plurality of bristles extending radially outward from aportion of said wire core, said plurality of bristles defining a bristleblock; and a protective tip homogeneously and integrally formed on saidwire core at said bristle end for preventing said brush from damagingsaid sensitive surfaces, said protective tip being formed by melting orwelding only said bristle end of said wire core such that saidprotective tip is made up of existing material from said wire corewithout the addition of any other quantity of material.
 12. The brush ofclaim 9, wherein: said protective tip is in the shape of a round ball.